The present invention relates to a programmable circuit breaker for switching off electric current, the circuit breaker comprising means to monitor the strength of the electric current and means for switching off the passage of the electric current through the circuit breaker.
Circuit breakers are used in a variety of environments to protect the environment and the users against faults in electric equipment and circuits. In a building, circuit breakers are generally placed in a centered manner in one location in connection with the building""s main power switch inside the building.
It is previously known to place, in connection with the circuit breaker, some kind of an adjustable timer apparatus, with the aid of which it is possible to restrict the passage of electric current to the circuit behind the circuit breaker as a function of time. The most typical application is socket posts intended for the heating of vehicles, which posts, in addition to the socket, usually also comprise an automatic circuit breaker and a timer, which is used to switch on the circuit at the desired time of day, typically for a few hours.
FIG. 1 presents an example of the structure of an arrangement based on prior art in connection with a socket post. The arrangement comprises a connection to an electrical network 100, a socket 102 for coupling the vehicle""s heater, an adjustable timer 104 which is used to set the desired switched-on time, a switch 106 which is controlled by the timer, and a device 108 which can be a conventional disposable fuse or a so-called circuit breaker. The known arrangements have been designed for single applications and their use is limited. In addition, their use requires fixed installations.
Further, so far it has not been possible to realize an effortless setting of time-based availability of electric current in electrical networks inside buildings. The timer switches used in industry are similar in structure to the above-mentioned solutions and require fixed installation.
There are also applications in which the setting of timer for the control of electric current must be possible only for certain persons. For example, in connection with sockets for catsxcx9c, this restriction of use is realized using lockable socket boxes. In buildings, this solution is impractical and requires separate installation. In old premises, this is not even possible owing to lack of space.
The object of the present invention is thus to realize an arrangement which can be used to effortlessly implement versatile timing in both new and existing buildings. The object of the invention is also to realize an arrangement which can be used to restrict the control of timing to certain persons or groups of persons.
This will be achieved with a circuit breaker of the type described in the preamble, which is characterized in that the circuit breaker comprises means to store one or more desired time periods, an interface to a separate programming device for the time periods and means to control the switching means on the basis of the time periods stored.
The invention also relates to a programming device for a timer, the device comprising a key pad, a display and an interface to the programmable device. The programming device according to the invention is characterized in that the device comprises means to store codes of different timers, means to store a security code which enables programming, and means to enable the use of the programming device when the stored security code is fed to the device.
The solution of the invention has many benefits. A programmable circuit breaker, such as in the invention, can be placed anywhere in place of a conventional circuit breaker, whereby the electrical network inside the building can be controlled on the basis of time. Thus, for example, the lighting of a room can be controlled by leaving the room""s light switch in the xe2x80x9conxe2x80x9d position and by using the circuit breaker to control the lights. The preferred embodiments of the invention can be seen in the independent claims.